Cartridge for Viscous Fluid Materials

ABSTRACT

A cartridge for storing and dispensing viscous fluid materials providing excellent productivity and gas barrier properties and free from external appearance defects at the site of film wrapping. The inventive cartridge for viscous fluid materials has a plunger  3  inserted into the bottom portion of a cartridge body  2  fabricated using insert injection molding by integrally molding a cylindrical barrel portion  5  of a multilayer structure produced by laminating a gas barrier layer  8  including a metal thin layer  8   a  on the exterior periphery or interior periphery of a plastic layer  7,  and a lid  6  covering the top of said cylindrical barrel portion.

TECHNICAL FIELD

The present invention relates to a cartridge used for storing viscousfluid materials, and, especially suitably, moisture-curable compositionssuch as sealing agents, and dispensing the materials onto surfaces to becoated at the moment of use.

BACKGROUND ART

Well-known containers used for storing sealing agents include plasticcartridges obtained by molding a lid having a discharge outletintegrally with the top end of a barrel portion made of plastic and,after filling it with a sealing agent, installing a plunger in theopening in the lower end of the barrel portion. Although polyethylene istypically used as the material used for the barrel portion and lid andthe thickness of the barrel portion walls, with account taken of therequired strength, weight, economic efficiency, etc., is normally set to1-1.5 mm, due to the characteristics of the material and the pinholesformed during molding, the walls exhibit a certain degree of airpermeability and their outside air-barrier properties are imperfect.

The use of such containers as containers for moisture-curable sealingagents has led to various problems associated with the penetration ofoutside air, and, in particular, permeation of moisture (water) insidethe containers. For instance, sealing agent curing occurs in theportion, where the sealing agent comes into contact with the surface ofthe interior walls of the barrel portion and in the portion around theplunger, as a result of which storage life deteriorates, thenonconforming article percentage increases, and dispensing the sealingagent using the plunger becomes difficult. In addition, if thetemperature of adherends such as glass plates, metal plates, metal sash,etc. is elevated, applying a sealing agent that has been stored in thecontainer for an extended period of time to said adherends results inthe formation of air bubbles at the interface between the sealing andthe adherends.

Japanese Patent Application Publication (JP-A) No. 2001-240154 and JP-ANo. 2003-104461 describe plastic cartridges for sealing agents producedby wrapping a composite film comprising an aluminum film around theexterior periphery of a cylindrical barrel portion constituted by aplastic molding. In such cartridges, gas barrier properties are impartedand the storage life of the sealing agents inside is improved bywrapping a composite film including an aluminum film around the exteriorperiphery of the cylindrical barrel portion.

However, the manufacture of the cartridges described in JP-A No.2001-240154 requires a composite film wrapping step separate from thestep of molding of the cartridge body, and consequently its productivityis not very high.

Moreover, when the composite film is wrapped around the exteriorperiphery of the cylindrical barrel portion, external appearance isdamaged because wrinkles tend to form easily and air remains in thewrinkled portions.

DISCLOSURE OF INVENTION

With account taken of the above-described problems, it is an object ofthe invention to provide a cartridge for storing and dispensing viscousfluid materials offering excellent productivity and gas barrierproperties and free from external appearance defects at the site of filmwrapping.

To attain the above-mentioned object, the present invention provides acartridge for viscous fluid materials, wherein a plunger used fordispensing contents filling a cartridge body is inserted in the bottomside of the cartridge body fabricated using insert injection molding byintegrally molding a cylindrical barrel portion of a multilayerstructure in which a gas barrier layer comprising a metal thin layer islaminated on the exterior periphery or interior periphery of a plasticlayer used to maintain the shape and strength of the cylindrical barrelportion itself, and a lid covering the top of said cylindrical barrelportion.

According to an embodiment of the cartridge for viscous fluid materialsprovided by the present invention, a gas barrier layer comprising theabove-mentioned metal thin layer may be laminated on the exteriorperiphery of the plastic layer of the above-mentioned cylindrical barrelportion.

According to another embodiment of the cartridge for viscous fluidmaterials provided by the present invention, the gas barrier layercomprising the metal thin layer and a layer producing no interactionwith the contents or allowing no components from the contents to passtherethrough may be laminated on the interior periphery of the plasticlayer of the cylindrical barrel portion.

Furthermore, in an embodiment having the gas barrier layer laminated onthe interior periphery of the plastic layer of the cylindrical barrelportion, the cylindrical barrel portion and the lid portion may beformed using injection molding by injecting PE, the layer producing nointeraction with the contents or allowing no components from thecontents to pass therethrough may be formed from any one of polyesters,polyamides, polyacrylic resins, heat-curable epoxy resins, UV-curableepoxy resins, or mixed resins of two or more components selectedtherefrom, and the contents include at least one component selected fromorganic solvents, hydrocarbon oils, and ketones.

The inventive cartridge for viscous fluid materials offers highproductivity because it permits integral molding of the cartridge bodyand the location of the gas barrier arranged in its cylindrical barrelportion using a single molding process.

In addition, because the cylindrical barrel portion of the cartridgebody is enclosed in the gas barrier layer comprising a metal thin layer,it has excellent gas barrier properties, in particular, moisture barrierproperties.

In the present invention, when the gas barrier layer is laminated on theexterior periphery of the plastic layer of the cylindrical barrelportion, the gas barrier layer is molded integrally with the cylindricalbarrel portion of cartridge body by insert injection molding, as aresult of which, unlike in case of wrapping a gas barrier film aroundthe barrel portion, no external appearance defects are produced at thesite of film wrapping because of wrinkles and residual air.

Moreover, when the gas barrier layer is laminated on the interiorperiphery of the plastic layer of the cylindrical barrel portion, evenif the injection molding resin constituting the primary molding materialof the cartridge body is a material that readily exhibits interactionwith the contents, the plastic layer made up of the injection moldingresin is protected from the contents by the gas barrier layer, therebyyielding a cartridge offering high durability to the contents or highstorage stability for the contents.

The above-mentioned cartridge is suitable for use as a cartridge filledwith a moisture-curable composition, such as a sealing agent, especiallya silicone-, silicone modified-, or polyurethane-based sealing agent.

BRIEF DESCRIPTION OF DRAWINGS

In the accompanying drawings,

FIG. 1 is an exploded perspective view illustrating an example of theinventive cartridge for viscous fluid materials;

FIG. 2 is a cross-sectional view illustrating an example of theinventive cartridge for viscous fluid materials; and

FIG. 3 is a cross-sectional view illustrating another example of theinventive cartridge for viscous fluid materials.

The reference numeral in each figure refers to the following: 1:cartridge, 2: cartridge body, 3: plunger, 4: nozzle, 5: cylindricalbarrel portion, 6: lid, 7: plastic layer, 8: gas barrier layer, 8 a:metal thin layer, 8 b: bonding layer, 8 c: outermost layer, 8 d: metalthin layer, 8 e: bonding layer, 8 f: outermost layer, 9: cylindricalopening portion, 9 a: Helical groove, 10: seal film, 11:pressure-application surface, and 12: cylindrical side surface.

BEST MODE FOR CARRYING OUT THE INVENTION

The inventive cartridge for viscous fluid materials is a cartridge,wherein a plunger used for dispensing contents filling a cartridge bodyis inserted in the bottom side of the cartridge body fabricated usinginsert injection molding by integrally molding a cylindrical barrelportion of a multilayer structure in which a gas barrier layercomprising a metal thin layer is laminated on the exterior periphery orinterior periphery of a plastic layer used to maintain the shape andstrength of the cylindrical barrel portion itself, and a lid coveringthe top of said cylindrical barrel portion.

FIG. 1 and FIG. 2 show an exploded perspective view and a schematiccross-sectional view of an example of the present invention, wherein acartridge, 1A, has a gas barrier layer laminated on the exteriorperiphery of the barrel portion of the cartridge body. As shown in FIG.1, cartridge 1A is composed of a cartridge body 2, in which a lid 6covers the top side of a cylindrical barrel portion 5; a plunger 3,which is inserted into the bottom of the cartridge body 2; and a nozzle4, which is attached as the occasion demands.

FIG. 2 is a cross-sectional view of cartridge 1A with the plunger 3 andnozzle 4 installed in the cartridge body 2. The cylindrical barrelportion 5 of the cartridge body 2 has a multilayer structure produced bylaminating, in the direction from the inside towards the outside on theexterior periphery of a plastic layer 7 used to maintain the shape andstrength of the cylindrical barrel portion itself, a gas barrier layer 8made up of a bonding layer 8 b used for boding to the plastic layer, ametal thin layer 8 a, and an outermost layer 8 c. In addition, aprotruding cylindrical opening portion 9 is formed in the center of thelid 6, a helical groove 9 a is provided on the exterior periphery of thecylindrical opening portion for threaded engagement with the nozzle 4,and a suitable seal film 10 made of aluminum foil etc. is attached usingan appropriate method, such as adhesion, fusion, etc., to the interiorsurface of the lid 6 in order to cover the cylindrical opening portion.

In the cartridge body 2, which is an integral molding formed usinginsert injection molding by arranging a gas barrier film serving as agas barrier layer inside a mold in a location corresponding to theexterior periphery of the cylindrical body and injecting molten resininto the mold, the plastic layer 7 of the cylindrical barrel portion andlid portion 6 are made up of the resin injected into the mold and thegas barrier layer portion 8 is made up of the gas barrier film insertedinto the mold.

The injection molding resin, which constitutes the primary moldingmaterial of the cartridge body 2, is subject to no particularlimitations so long as it is a plastic material satisfying requirementsin terms of the shape, strength and other physical properties requiredfor the cartridge body and so long as it has the stability required toprevent interaction with the contents. In general, suitable resinsinclude polyolefin resins, such as LDPE, HDPE, LLDPE, and otherpolyethylenes (PE), polypropylene, etc., as well as mixed resinscomprising said polyolefin resins as the main ingredients.

In order to ensure gas barrier properties and, in particular, sufficientmoisture barrier properties, the gas barrier film serving as the gasbarrier layer of the cartridge body has at least a metal thin layer.Aluminum foil and aluminum deposition-layers are preferred as the metalthin layers, but foil and deposition-layers of other metallic materialsmay be used as well. It is only necessary for the gas barrier film tocomprise a metal thin layer, which may be a single layer film made up ofmetal foil or a composite film where other layers are provided on one orboth sides of a metal thin layer.

For instance, in order to firmly bond the injection molding resin to thegas barrier film, the gas barrier film is preferably a composite film,in which a bonding layer 8 b made up of a resin exhibiting high adhesiveproperties with respect to the injection molding resin is provided onone side of a metal thin layer. Moreover, the gas barrier film may berepresented by a composite film having an outermost layer 8 c used forprotecting the metal thin layer provided on one side of the metal thinlayer. From the standpoint of adhesive properties, the same type ofmaterial as the material of the plastic layer (e. g. either one of LDPE,HDPE, or LLDPE in case of LDPE, HDPE, or LLDPE) is preferable for use inthe bonding layer 8 b. In addition, the outermost layer 8 c may beformed from the same type of plastic material as the bonding layer 8 b.

When PE is used as the injection molding resin, a suitable gas barrierfilm is obtained by laminating a PET layer with a thickness of 5-100 μmand a biaxially-oriented polypropylene layer (OPP layer) with athickness of 5-100 μpm, which serves as the outermost layer, on one sideof aluminum foil with a thickness of 5-100 μm and laminating a PE layerwith a thickness of 10-50 μm, which serves as the bonding layer, on theother side. Moreover, also suitable is a gas barrier film obtained bylaminating an OPP layer with a thickness of 5-100 μm serving as anoutermost layer on one side of an aluminum deposition PET film producedby providing a 1-10 nm aluminum deposition-layer on one side of a PETbase film with a thickness of 10-100 μm, and laminating a PE layer witha thickness of 10-50 μm serving as a bonding layer on the other side.

The thickness of the aluminum foil and aluminum deposition film ispreferably within the above-described ranges, because in such a case fewpinholes develop in the aluminum layer and its flexibility may not beimpaired. In addition, the thickness of the PE layer is preferablywithin the above-described range because the bonding layer then mayexhibit sufficient adhesion and may not be excessively thick.

A cartridge body with an outside diameter of 30 to 100 mm, a length of150 to 250 mm (excluding the cylindrical opening portion), a wallthickness of 0.5 to 2 mm in the cylindrical barrel portion, and a lidthickness of 0.5 to 2 mm can be molded by inserting such a barrier filminto a mold in the position corresponding to the exterior periphery ofthe cylindrical body and injecting molten PE into the mold. The name ofthe product and the contents, manufacture date, manufacturer, and otherinformation can be indicated by printing it on the exterior periphery ofthe barrel portion of the cartridge body.

The plunger 3, which is inserted into the bottom portion of thecartridge body 2, has a pressure-application surface 11, which comesinto contact with the contents, and a cylindrical side surface 12, whichis tightly engaged with the interior surface of the cylindrical barrelportion 5 of the cartridge body 2 and is slidably movable therein in afluid-tight manner when pressed inside the cartridge body. The plunger 3is typically a bottomless hollow cylinder, with the piston of adispensing implement, not shown, pressing against the hollow recessedportion thereof. There are no particular limitations concerning thematerial used for the plunger, which may be molded from the same plasticmaterial as the cartridge body.

In addition, it is only necessary to install the nozzle 4 in thecylindrical opening portion 9 of the lid at the moment of use and itdoes not have to be installed when the cartridge is in storage. Thereare no particular limitations concerning the material used for thenozzle, which may be molded from the same plastic material as thecartridge body.

FIG. 3 is a schematic cross-sectional view of another example of thepresent invention, wherein a cartridge, 1B, has a gas barrier layerlaminated on the interior periphery of the barrel portion of thecartridge body.

In the explanations of cartridge 1B provided below, explanationsconcerning portions common with cartridge 1A are omitted, with theexplanations focusing mainly on the portions characteristic of cartridge1B. In addition, for portions common with cartridge 1A, the samereference numerals are used in the figure illustrating cartridge 1B asin the figure illustrating cartridge 1A.

Although cartridge 1B has the same external appearance as cartridge 1Aillustrated in the above-described FIG. 1, the cross-sectional structureof the barrel portion of the cartridge body is different from that ofcartridge 1A.

Namely, as shown in FIG. 3, in the cartridge body 2 of cartridge 1B, thecylindrical barrel portion 5 has a multilayer structure produced bylaminating, in the direction from the outside towards the inside on theinterior periphery of a plastic layer 7 used for maintaining the shapeand strength of the cylindrical barrel portion itself, a gas barrierlayer 8 made up of a bonding layer 8 e, which is used for bonding to theplastic layer, a metal thin layer 8 d, and an innermost layer 8 f.

In this case the cartridge body 2 is an integral molding formed usinginsert injection molding by arranging a gas barrier film serving as agas barrier layer inside a mold in a location corresponding to theinterior periphery of the cylindrical body and injecting molten resininto the mold, wherein the plastic layer 7 of the cylindrical barrelportion and the lid portion 6 are made up of the resin injected into themold and the gas barrier layer portion 8 is made up of the gas barrierfilm inserted into the mold.

In general, if the injection molding resin used to form the plasticlayer 7 of the cylindrical barrel portion of the cartridge body 2 is amaterial readily producing interaction with the contents (in otherwords, a material readily swelling in the presence of the contents, amaterial quickly deteriorating in the presence of the contents, or amaterial quickly dissolving in the contents and causing itsdeterioration), the swelling of the cartridge body 2 results in theleakage of the contents, imperfect engagement between the plunger andthe body, and aeration of the contents, or, otherwise, contact betweenthe injection molding resin and the contents causes the contents and thecartridge to deteriorate.

For instance, if solvents such as toluene, benzene, xylene, and otherorganic solvents; liquid paraffin and other hydrocarbon oils; acetoneand other ketones are included in the contents, the resin of thecartridge body swells, gaps appear between the interior surface of thebarrel portion and the pressing plunger fitted inside, the contentsleak, and dispensing is unstable when applying pressure to the contents.

Moreover, if air is incorporated into the contents through such gapsbetween the interior surface of the barrel portion and the plunger, thismay negatively affect the quality of the contents. For instance, if thecontent is a sealing agent, there may be a chance that moisturecontained in the air may damage the stability of the contents andsealing may be defective due to the inclusion of air in the locationwhere the contents are injected.

By contrast, contact between the plastic layer 7 of the cylindricalbarrel portion and the contents is avoided by providing the gas barrierlayer 8 on the interior periphery of the cylindrical barrel portion ofthe cartridge body 2 and, as a result, the occurrence of theabove-described interaction is prevented and a cartridge is obtainedthat has high durability to the contents, or offers high storagestability for the contents.

If the metal thin layer of the gas barrier film is made up of metalfoil, contact with the plastic layer 7 of the cylindrical barrel portionand the contents can usually be easily avoided. From the standpoint offurther improving the durability of the container and the storage lifeof the contents, it is preferable to provide a layer that does not allowthe contents to pass therethrough (in particular, organic solvents,hydrocarbon oils, and ketones in the contents) adjacent the metal thinlayer or between the metal thin layer and another layer.

In the present invention, the expression “a layer producing nointeraction with the contents or allowing no components from thecontents to pass therethrough” means that a certain layer, which thatdoes not cause any alteration of the contents or the container ordegradation in the storage life of the contents or the durability of thecontainer, does not produce any interaction with the entire formulationof the contents or any interaction with one, two, or more components inthe formulation, and, even if the interaction does occur, theinteraction does not present any problems in practical terms; and, thata layer does not allow any components from the contents to passtherethrough, or even if it does, it does not allow an amount to passtherethrough that would cause any alteration of the contents or thecontainer or any degradation in the storage life of the contents or thedurability of the container that would present problems in practicalterms. In this sense, interaction or penetration at levels that can beignored in practical use is permissible.

For instance, in cartridge 1B, the innermost layer 8 f of the gasbarrier layer 8 can be made chemically stable with respect to thecomponents and solvents included in the contents filling the cartridge,or can be formed from resin that does not allow them to passtherethrough.

Resins suitable for the innermost layer are exemplified by polyethylene,polypropylene, and other polyolefins; Nylon-6, Nylon-6,6, and otherpolyamides; polyethylene terephthalate, polynaphthalates, and otherpolyesters; polyacrylic resins; and heat-curable and UV-curable epoxyresins, etc. Among them, polyester resins of superior solvent resistanceand economic efficiency are preferable, and among these, polyethyleneterephthalate is even more preferable.

When the gas barrier film is arranged on the interior of the barrelportion, the gas barrier film is preferably a composite film, in whichthe innermost layer is provided on one side of the metal thin layer and,on the other side, there is provided a bonding layer 8 e made up ofresin possessing high adhesive properties with respect to the injectionmolding resin in order to firmly bond the gas barrier film to theinjection molding resin. From the standpoint of adhesive properties, thesame type of material as the material of the plastic layer (e. g. eitherone of LDPE, HDPE, or LLDPE in case of LDPE, HDPE, or LLDPE) ispreferable for use in the bonding layer 8 e.

When PE is used as the injection molding resin, a gas barrier film issuitably used that is obtained by laminating a PET layer with athickness of 5-100 μm and an OPP layer with a thickness of 5-100 μmserving as the innermost layer on one side of aluminum foil with athickness of 5-100 μm and laminating a PE layer with a thickness of10-50 μm serving as a bonding layer on the other side. Moreover, alsosuitable is a gas barrier film obtained by laminating an OPP layer witha thickness of 5-100 μm serving as an innermost layer on one side of analuminum deposition PET film produced by providing a 1-10 nm aluminumdeposition-layer on one side of a PET base film with a thickness of10-100 μm and laminating a PE layer with a thickness of 10-50 μm servingas a bonding layer on the other side.

The cartridge body 2 of cartridge 1B can be molded by inserting such agas barrier film into the mold in a position corresponding to theinterior periphery of the cylindrical body and injecting molten PE intothe mold.

In cartridge 1B, the same components as in cartridge 1A can be used forthe nozzle 4 and the plunger 3 inserted into the bottom of the cartridgebody 2. It should be noted that when the contents filling the cartridgecomprise solvents etc., it is preferable to use a plunger 3 made ofmetal or a plunger 3 in which at least the pressure-application surface11 is formed from the same material as the above-mentioned cartridgebody 2.

At the time of use, the above-described cartridges 1A and 1B are used todischarge the contents by breaking the seal film 10 to open thecylindrical opening portion, attaching the nozzle 4, and pushing theplunger 3 inside toward the top end of the cartridge body 2.

Although the cartridge allows for various viscous fluid materials to befilled, stored, and discharged as the contents, the cartridge issuitable for use as a cartridge filled with a moisture-curablecomposition, such as a sealing agent, and especially a silicone-,silicone modified-, or polyurethane-based sealing agent.

The above-described inventive cartridge for viscous fluid materialsoffers high productivity and cost reductions because it permits integralmolding of the cartridge body with the location of the gas barrier layerarranged in its cylindrical barrel using a single molding process.

In addition, because the cylindrical barrel portion of the cartridgebody is enclosed in the gas barrier layer comprising a metal thin layer,it has excellent gas barrier properties, in particular, moisture barrierproperties.

Moreover, unlike wrapping a gas barrier film around the barrel portion,no external appearance defects, such as wrinkles and air inclusions (airbubbles remaining between the film and the cylindrical barrel portion),are generated because the gas barrier layer is made integrally with thecylindrical barrel portion of the cartridge body using insert injectionmolding even when the gas barrier layer 8 is laminated on the exteriorperiphery of the cartridge body, as in case of the above-mentionedcartridge 1A.

Furthermore, when the gas barrier layer is laminated on the interiorperiphery of the cartridge body, as in the above-mentioned cartridge 1B,even if the injection molding resin constituting the primary moldingmaterial of the cartridge body is a material that readily exhibitsinteraction with the contents, the plastic layer made up of theinjection molding resin is protected from the contents by the gasbarrier layer and, as a result, a cartridge is obtained that provideshigh durability to the contents or high storage stability for thecontents.

EXAMPLES

The moisture permeability of the inventive cartridge, as well as thestorage stability of sealing agents (micro-particles of cured material,foaming), were investigated to confirm the effects of the invention.

Example 1

A cartridge body A having a cylindrical barrel portion provided with agas barrier layer 8 on its exterior periphery, such as the one shown inFIG. 1 and FIG. 2, was fabricated by insert injection molding usingpolyethylene resin as the injection molding resin and a composite filmhaving a layered structured obtained by laminating a PE layer, AL foil,a PET layer, and an OPP layer as an insert film for a gas barrier layer.

The resultant cartridge body 1A has a shape, in which one end of thecylindrical barrel portion is covered with a lid portion 6 provided witha cylindrical opening portion (discharge portion) in the center thereof,with the body having an internal diameter of 48 mm, a total inner lengthof 213 mm, and a volume of approximately 381 mm³. Its cross-sectionalstructure is a layered structure, in which there is a plastic layer 7made entirely of high-density polyethylene resin, the wall thickness ofthe cylindrical barrel portion is 1.15 mm, and a gas barrier layer madeup of a PE bonding layer, an AL foil layer, a PET layer, and anoutermost OPP layer is provided on the exterior periphery thereof.

The cylindrical opening portion 9 of cartridge body A is sealed byfusing a seal film 10 made up of aluminum laminated film to the interiorsurface of the lid portion 6. A tapered nozzle 4 made of low-densitypolyethylene is threadedly engaged with the cylindrical opening portion9.

In order to enhance airtightness when fitting the pressing plungerinside the interior surface of the opening portion at the other end ofcartridge body A, a mixture of polybutene and microcrystalline wax(mixing ratio: 6:4) is applied to a region extending up to 50 mm fromthe other end of the interior peripheral surface of the cartridge body.

Example 2

A cartridge body B having a cylindrical barrel portion provided with agas barrier layer on the interior periphery thereof, such as the oneshown in FIG. 1 and FIG. 3, was fabricated by insert injection moldingusing the same injection molding resin and composite film as in Example1.

The shape and dimensions of the resultant cartridge body B wereidentical to those of Example 1. Its cross-sectional structure, however,was a layered structure, wherein a gas barrier layer made up of a PEbonding layer, an AL foil layer, a PET layer, and an innermost OPP layerwas provided on the interior periphery of the cylindrical barrelportion.

In the same manner as in Example 1, cartridge body B had a seal film 10fused to the lid portion 6, a threadedly engaged nozzle 4, and a mixtureof polybutene and microcrystalline wax (mixing ratio: 6:4) applied tothe interior peripheral surface of the opening portion at the other end.

Comparative Example 1

A cartridge body C with a cylindrical barrel portion that did not have agas barrier layer was fabricated by insert injection molding using thesame injection molding resin and lid portion as in Example 1, butwithout using the composite film.

The shape and dimensions of the resultant cartridge body C wereidentical to those of Example 1. However, its cross-sectional structuredid not have a gas barrier layer.

In the same manner as in Example 1, cartridge body C had a seal film 10fused to the lid portion 6, a threadedly engaged nozzle 4, and a mixtureof polybutene and microcrystalline wax (mixing ratio: 6:4) applied tothe interior peripheral surface of the opening portion at the other end.

<Tests> (1) Moisture Permeability of Cartridge

The cartridge bodies obtained in Examples 1 and 2 and in ComparativeExample 1 were filled with 30 g of calcium chloride and tightly sealedby fitting therein a pressing plunger 3 with a wall thickness of 1.1 mmmade of the same high-density polyethylene as each of the cartridgebodies. The cartridges were held for 20 weeks at a temperature of 40° C.under an atmosphere that had a relative humidity of 90%, whereuponmoisture permeability (mg) was obtained from the increase in weight.

(2) Storage Stability of Moisture-Curable Sealing Agents [Preparation ofMoisture-Curable Silicone Sealing Agents and Aging Procedures]

A dealcoholation-type moisture-curable silicone sealing agent A wasprepared by mixing 50 parts by weight of a polydimethylsiloxane with aviscosity of 17000 mPa-s at 25° C. having both terminal ends of themolecular chain blocked with dimethylhydroxysiloxy groups, 50 parts byweight of calcium carbonate (prepared by precipitation, with a BETspecific surface area of 18 m²/g and surface-treated with fatty acid),3.0 parts by weight of methyltrimethoxysilane, and 1.0 part by weight ofdi(isopropoxy)titanium-di(ethylacetoacetate) to homogeneity at roomtemperature. Here, the term “BET specific surface area” refers to a BETspecific surface area obtained by the nitrogen adsorption method. Inaddition, the term “dealcoholation-type” refers to a type, whereinalcohol is obtained as a reaction by-product when cured, with thealcohol in many cases capable of forming gas bubbles in the sealingagent by vaporization.

The cartridge bodies A of Example 1 were filled with the above-describedmoisture-curable silicone sealing agent A and tightly sealed by fitting,in the opening section, a pressing plunger 3 with a wall thickness of1.1 mm fabricated by injection molding using the same high-densitypolyethylene as the cartridge bodies A. The cartridges A filled withsuch a silicone sealing agent were left to stand for 4 weeks, 8 weeks,12 weeks, 16 weeks and 20 weeks under an accelerated aging condition ata temperature of 20° C. that had a relative humidity of 90%. The testsdescribed below were performed on cartridges after each aging period toinspect for the presence of cured material and forming. In addition, thesame tests were conducted on cartridge bodies obtained in other examplesand in the Comparative Example.

[Inspection for Cured Material]

The moisture-curable silicone sealing agent A that had been stored underthe accelerated aging condition for a predetermined period of time asdescribed above, was discharged from the cartridges A and visuallyexamined for the presence of micro-particles of cured material.

[Inspection for Foaming]

A joint was provided by arranging two 12 mm×50 mm×6 mm(width×length×height) strips of backup material parallel to each other,with an interval of 12 mm, on a 50 mm×50 mm×5 mm glass test panel. Theglass test panel was placed in an oven at 50° C. and removed from theoven 24 hours later, whereupon the moisture-curable silicone sealingagent A that had been held for the predetermined period of time underthe same conditions as in the above-described storage stability test(2), was immediately applied into the joint and, after touching it upwith a spatula, the silicone sealing agent was then cured by keeping itfor 7 days at a temperature of 25° C. under an atmosphere that had arelative humidity of 50%. Subsequently, the interface between thesilicone sealing agent and the glass test panel was examined for thepresence of air bubbles.

(3) Storage Stability of Hydrocarbon Oil-Containing Sealing Agents

[Preparation of Hydrocarbon Oil-Containing Moisture-Curable SiliconeSealing agents and Aging Procedures]

A dealcoholation-type moisture-curable silicone sealing agent B wasprepared by mixing 50 parts by weight of a polydimethylsiloxane with aviscosity of 17000 mPa-s at 25° C. having both terminal ends of themolecular chain blocked with dimethylhydroxysiloxy groups, 15 parts byweight of liquid paraffin (HYDROSEAL G 400H from TOTAL SOLVENTS), 50parts by weight of calcium carbonate (prepared by precipitation, with aBET specific surface area of 18 m²/g and surface-treated with fattyacid), 3.0 parts by weight of methyltrimethoxysilane, and 1.0 part byweight of di(isopropoxy)titanium-di(ethylacetoacetate) to homogeneity atroom temperature.

The cartridge bodies B obtained in Example 2 were filled with theabove-described moisture-curable silicone sealing agent B and tightlysealed by fitting, in the opening section, a pressing plunger 3 with awall thickness of 1.1 mm fabricated by injection molding using the samehigh-density polyethylene as the cartridge bodies B. The cartridges Bfilled with such a silicone sealing agent were held for 240 hours, 550hours, 840 hours, and 1200 hours under an accelerated aging condition ata temperature of 25° C. that had a relative humidity of 50%. The testsdescribed below were run on cartridges after each aging period toinspect for the change of cartridge body total length and presence ofliquid paraffin. In addition, the same tests were conducted on cartridgebodies obtained in Example 1 and in Comparative Example 1.

[Inspection for Change of Cartridge Body Total Length]

The total length in the longitudinal direction of the cylindrical barrelportions of the cartridge bodies A-C filled with the moisture-curablesilicone sealing agent B prior to holding them was subjected tomeasurement. The measured values were used as the initial total length(mm) of the cartridge bodies.

Subsequently, the total length of the cartridge bodies A-C filled withthe silicone sealing agent, which had been stored for a predeterminedperiod of time, as mentioned above, under the accelerated agingcondition, was subjected to measurement and expressed as a difference(mm) from the initial total length of the cartridge bodies.

[Inspection for Liquid Paraffin]

The cartridge bodies A-C filled with the silicone sealing agent wereleft to stand for 1200 hours, whereupon the cartridge bodies were cut intwo to check for air penetration and presence of cured material aroundthe plunger. Because when air penetration was present, voids weregenerated inside the cartridge and liquid paraffin separated from thesealing agent at the interface with the voids bled out, air penetrationwas determined by visually checking for the presence of liquid paraffinseparation. At such time, cases wherein no liquid paraffin separationwas found around the plunger were designated as “o”; cases whereinslight separation was found were designated as “Δ”; and cases whereinclear separation was found were designated as “x”.

Moreover, examination was conducted to determine whether any curedmaterial was present in the moisture-curable silicone sealing agent B ofthe severed cartridge bodies.

<Test Results>

Table 1 below lists the results obtained by examining the cartridgebodies A-C fabricated in the Examples and in the Comparative Example todetermine their moisture permeability, the presence of micro-particlesof cured moisture-curable silicone sealing agent A contained in thecartridges, and the presence of foaming.

The cartridge of Example 1, which utilizes a cartridge body A having agas barrier layer provided on the exterior periphery of the cylindricalbarrel portion, and the cartridge of Example 2, which utilizes acartridge body B having a gas barrier layer provided on the exteriorperiphery of the cylindrical barrel portion, have low moisturepermeability, with no cured material produced inside the cartridges andno sealing agent foaming occurring in the test panel joint even afterleaving the cartridges to hold for 20 weeks under accelerated agingconditions.

By contrast, the cartridge of Comparative Example 1, which utilizedcartridge body C that had no gas barrier layer 8 provided in thecylindrical barrel portion, exhibited high moisture permeability,produced sealing agent foaming after holding for 12 weeks, and producedcured material in the cartridge after holding for 16 weeks under theaccelerated aging conditions.

Furthermore, Table 1 lists the results obtained by examining thecartridge bodies A-C prepared in the Examples and in the ComparativeExample to determine the total length of the cartridges after holdingfor the prescribed time, air penetration, and the presence ofmicro-particles of cured moisture-curable silicone sealing agent Bcontained in the cartridges.

The cartridge of Example 2, which utilized cartridge body B having a gasbarrier layer provided on the interior periphery of the cylindricalbarrel portion, and that of Example 1, which utilized cartridge body Ahaving a gas barrier layer provided on the exterior periphery of thecylindrical barrel portion, exhibited a change of below than 1 mm in thetotal length of the cartridge body even after holding for 1200 hoursunder accelerated aging conditions. Moreover, there was almost no liquidparaffin exudate generated due to air penetration around the plunger andno cured material was produced inside the cartridge even after holdingfor 1200 hours under accelerated aging conditions. In particular,cartridge body B used in Example 2, which had a gas barrier layerprovided on the interior periphery of the cylindrical barrel portion,revealed no liquid paraffin exudate due to air penetration and thus hadextremely good gas barrier properties.

By contrast, after holding for 840 hours under accelerated agingconditions, the cartridge of Comparative Example 1, which utilizedcartridge body C having no gas barrier layer in the cylindrical barrelportion, exhibited a change of over 1 mm in the total length of thecartridge body. Moreover, there was liquid paraffin exudate generateddue to air penetration around the plunger and cured material wasproduced inside the cartridge after holding for 1200 hours underaccelerated aging conditions.

TABLE 1 Comparative Example 1 Example 2 Example 1 Moisture 60 60 450permeability (mg) Long-term storage stability Cured Foaming CuredFoaming Cured Foaming After 2 weeks No None No None No None After 4weeks No None No None No None After 8 weeks No None No None No NoneAfter 12 weeks No None No None No Yes After 16 weeks No None No None YesYes After 20 weeks No None No None Yes Yes Total length of 216.7 216.7216.3 cartridge body (mm): Initial After 240 hours 0.2 0.0 0.3 After 550hours 0.3 0.1 0.7 After 840 hours 0.5 0.0 1.1 After 1200 hours 0.7 0.11.4 Aeration Δ ∘ x Cured material None None Yes

1. A cartridge for viscous fluid materials, wherein a plunger used fordispensing contents filling a cartridge body is inserted in the bottomside of the cartridge body fabricated using insert injection molding byintegrally molding a cylindrical barrel portion of a multilayerstructure in which a gas barrier layer comprising a metal thin layer islaminated on the exterior periphery or interior periphery of a plasticlayer used to maintain the shape and strength of the cylindrical barrelportion itself, and a lid covering the top of said cylindrical barrelportion.
 2. The cartridge for viscous fluid materials according to claim1, wherein the gas barrier layer comprising the metal thin layer islaminated on the exterior periphery of the plastic layer of thecylindrical barrel portion.
 3. The cartridge for viscous fluid materialsaccording to claim 1, wherein the gas barrier layer comprising the metalthin layer and a layer producing no interaction with the contents orallowing no components from the contents to pass therethrough islaminated on the interior periphery of the plastic layer of thecylindrical barrel portion.
 4. The cartridge for viscous fluid materialsaccording to claim 3, wherein the cylindrical barrel portion and the lidportion are formed using injection molding by injecting PE, the layerproducing no interaction with the contents or allowing no componentsfrom the contents to pass therethrough is formed from any one ofpolyesters, polyamides, polyacrylic resins, heat-curable epoxy resins,UV-curable epoxy resins, or mixed resins of two or more componentsselected therefrom, and the contents include at least one componentselected from organic solvents, hydrocarbon oils, and ketones.
 5. Thecartridge for viscous fluid materials according to claim 1, which isfilled with a moisture-curable composition.